Tuesday, October 25, 2011

More facts that lie

Goebbels advocated "the big lie": if the lie is big enough, brazen enough and told often enough, people will believe it. But why lie when you can mislead with the truth? You can't be accused of the heinous crime of lying; the worst they can pin on you is the vague offence of mendacity, and most people don't even know what that means. 

Newspapers love surveys, and I've written before about those pure little numbers we call statistics with their objective, unspinnable and above all reassuring percentage signs. 

Readers and editors should always check for outright errors in calculation – a piece I was editing yesterday claimed that an increase from 255,000 to 1.45 million was 1,292% – and for flaws in method, but usually the numbers are correct and the facts can't be denied. That doesn't mean they mean what they want you to think they mean. The next question for the sceptical reader is, so what?

A prime example appears in today's Guardian, under the headline 'Eight revolting hygiene facts'. I don't know why this appeared today: there's no story attached and no 'according to a survey released by…' tag. Just a slack day on the news desk, I guess. They must be missing Colonel Gadaffi. 

The first revolting fact is that old chestnut, "The average chopping board contains 200% more bacteria than the average toilet seat."

Horrible, isn't it? No, not really. I'm sure the chopping boards and toilet seats in my house are fairly normal, and I'm not in the mood to go knocking on my neighbours' doors to get my own representative sample. So let's use common sense. What comes into contact with your toilet seat? Your bottom. The outside of your bottom, which is little more than an extenstion of the back of your thighs. If you're showering every day and wearing clean clothes, just how dirty are the backs of your thighs going to get? Chances are, you've even kissed someone's bare thigh without worrying about poisoning yourself. 

Your chopping board, on the other hand, comes into contact with all kinds of food and gets scoured by knives, creating cosy little niches where germs can flourish. Of course your chopping board has more bacteria than your toilet seat. I'm surprised it's only 200% more. 

This bit of scaremongering works by invoking the word 'toilet' and allowing our own associations with that piece of sanitary ware to fill in the gaps with our own assumptions. Nobody lied to you. They just made it easy to lie to yourself and then left you to it.

Let's look at Revolting Fact Number 3: "The salad drawer of your fridge may contain more than 750 times the level of bacteria deemed safe." The more you look at it, the more startling that statement is. Since the safe level is presumably the point above which one person could be poisoned, 750 times that level is enough to poison 750 people. Not only is it saying that your salad drawer could poison you, it's actually saying that it could poison nearly a thousand people. One salad drawer, 750 people.

It's a classic piece of churnalism. The link goes to the Huffington Post, which itself is churning something from the Daily Mail. The Mail's piece came from a survey commissioned by Microban, which (believe it or not) manufactures bacterial protection systems. 

The numbers could have been worse because 750 was only the average. The worst fridge Microban tested (of 30) had 12,900 times the safe bacterial limit. So the Guardian could have said, "The salad drawer of your fridge could contain enough bacteria to poison 13,000 people" without misrepresenting the survey (take that rogue fridge out of the sample, and the average is more than halved). 

So, what's wrong with that? Unlike with the toilet seat, we can't rationalise it to find exactly where the flaw lies. We simply need to use common sense. If there were enough bacteria in some fridges to poison a tenth of the population of Basingstoke (and without speculating on how desirable that might be), then the population of the western world would be practically annihilated the next time there was a heatwave, leaving only a few vegans and fruitarians with smug looks on their faces. The fact is, exposure to bacteria helps improve our resistance, which is one reason why the bacterial apocalypse hasn't happened. When it does, I reckon those with obsessively clean kitchens will be the first to go.

You should still clean out your fridge and clean your chopping board more often than you probably do. But without a survey backed by statistics, where's the news story? And anyone who thinks kissing thighs is hazardous can kiss my arse.

Moral: One of the most important questions to ask is 'Really?', closely followed by 'So what?'

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1 comment:

  1. Fascinating. So what should the Guardian sub-editor have done?

    ReplyDelete